Finned type cooling unit



May 24, 1938. R. w. KRITZER ET AL FINNED TYPE COOLING UNIT Filed Feb. .7, 1935 F re 4.

lnve nlora Patented Ma 24, 1 93s I I 2,118,206

UNITED STATES PATENT OFFICE FINNED TYPE COOLING UNIT Richard 'w. Kritzer and Anthony F. Hoesel, Chicago, lll., assignors to Peerless of America, Chicago, 111., a corporation of Illinois Application February '1, 1935, Serial No. 5,398

Claims. (Cl. 257-455) The type of coils, to which the invention relates, Figure 4 shows a spiral ribbon 26, which has a are well known in the art, and generally desigpitch 21. The outside diameter 28 is somewhat nated as fin coils. These fin coils are comprised larger than that of the internal diameter of a of the combination of a refrigerant conduit havrefrigerant conduit into which the spiral ribbon 5 ing parallel courses upon which are mounted, in- 26' is introduced by means of passing a bar 5 thermal relationship, a multiplicity of fin surthrough the inside bore of the refrigerant conduit faces for the purposes of increasing the effective prior to the bending of the return bends. The heat transfer surface, and to facilitate the deend of the spiral ribbon is attached to the aforefrosting of the cooling unit during the stoppage of said bar which by being rotated in the proper the refrigerant circulation through the refrigdirection also rotates the spiral ribbon in the 10 crant conduit. 7 proper direction. so that while the frictional en- One object of our invention. is to increase the gagement of the outside diameter of. the spiral thermal efficiency of fin coils, thereby enabling a ribbon with the inside diameter of the refrigerant smaller amount of material to effectuate the same conduit produces a frictional drag, the spiral heat transfer, at given temperature differences, ribbon in turn, due to its proper rotations, tends 15 as would be obtained with a much greater amount to increase its pitch and consequently decrease of material fabricated and assembled in the usual its outside diameter. These two tendencies autocompactly nested form. v matically balance themselves so that whenever Another object of our invention is to facilitate the spiral ribbon is rotatively pulled through the,

30 the defrosting of fin coils, and especiallyso, the refrigerant conduit, it is in tight engagement with lowermost fins of a cooling unit comprised of a the inwrnal walls of the refrigerant conduit. plurality of vertical fins. The purpose of the spiral ribbon isto convert the In the drawing: normal passage velocity, of a refrigerant inside a Figure 1 is an end elevational view partly in conduit, into that of a rotary motion, whereby section of afin coil fabricated in accordance with the liquid is thrown into engagement with' the 25 our invention. internal walls of the conduit, rather than flowin Figure 2 is a side elevational view of Figure 1. in the bottom portion only of the conduit. This Figure 3 is an isometric view of an end tie plate increase of. wetted wall surface results in an acmeans as embodied in the invention. celeration .of the vaporization of the liquid and I Figure 4 shows a spiral ribbon, which is placed consequently a greater heat absorption for a given 30 inside the refrigerant conduits. I length of conduit. The functions of this spiral Referring to the drawing: ribbon 26, and other alternatives producing the Figures 1 and 2 show a refrigerant conduit 5 same result, namely the rotation of the refrigerformed of a single continuous tube bent into zigant within the conduit, are more fully disclosed 5 zag form. A plurality of square fins 6 are spaced in the Richard W. Kritzer and Anthony F. Hoesel apart upon the straight portions or courses of application, Serial'Number 758,065 filed Decemthe conduit, but no fins are placed upon the reber 18, 1934.

turn bend portions 1. The fins are solocatedupon In all convection circulation cooling units,

the courses thattheir diagonals are vertical and the warm air enters at the top and 'sides, and the horizontal. End plates 8 through which the recold air drops from the bottom, due to cooling 0 turn bends project, hold the several courses of of the air producing decreased volume, and conthe coil in proper spaced relation to each other. sequently greater weight of the air perunit vol- The above form of construction is clearly outume.

lined in the Anthony F. Hoesel applications, Serial By means of placing fins upon a refrigerant 5 No. 591,086 filed February 5, 1932, which has since conduit in the manner described above, we have matured into Patent No. 1,988,494, dated January found that more air will pass through the cooling 22, 1935, and Serial No. 710,262 filed February 8, unit. This tends to resolve itself into greater 1934, now Patent No. 2,065,586, issued Dec. 29, convection air circulation at an increased tem- 1936 respectively, for the coil and a machine for perature after passing through our coils as comfabricating the same. pared with a lesser convection air circulation at 50 In Figure 3, the end plate 23 has slots 24 and a lower temperature after passing through other holes 25 through which project the return bends types of coils not employing our invention. While and the end portions respectivelyv of a cooling unit the air issuing from our coil is of a somewhat made in accordance with the above description 0 higher temperature, than that of the convection Figures 1 and 2. circulated air of other type of coils, the increased 55 quantity of convection circulation provides a net gain in the amount of heat transferred from the air to the cooling coil.

The above relates to cooling coils of the form disclosed in the drawing but without having the spiral ribbon inserted within the refrigerant conduit. After inserting the spiral ribbon we then find that the efficiency of the cooling coil is materially increased and the increased convection air circulation is maintained, and in many cases increased, and the temperature of the air, after passing through the cooling coil, is materially decreased, which results in getting a greater heat transfer from a given amount of material comprising the cooling coil as compared to the heat transfer of an equivalent amount of material fabricated into other types of coils.

We have further found that positioning the fins as shown in the drawing results in a ready defrosting of the cooling coil, since at least some of the corners of all the fins are subject to circulation of air, which is only partly cooled, whereas ;the close nesting of the fins, as generally employed, results in a delayed defrosting, which, in an automatic refrigerating systemjwould prove objectionable.

We claim:

1. In a cooling unit, the combination of parallel spaced apart refrigerant conduit courses, a multiplicity of substantially rectangultr and spaced apart fins mounted upon and individual to a single course, the diagonal lines of the fins being in substantially vertical and horizontal planes, and end means to maintain the spaced apart relationship of .the conduit courses.

2. In a cooling unit, the combination of parallel spaced apart refrigerant conduit courses, a multiplicity of substantially rectangular and spaced apart fins mounted upon and individual to a single course, the diagonal lines of the fins being in substantially vertical and horizontal planes, andlend means to maintain the spaced apart relationship of the conduit courses, the said conduit.

end means comprising a plate with slots, through which project the return bends joining adjacent courses of the refrigerant conduit.

3. In a cooling unit, the combination of parallel spaced apart refrigerant conduit courses, a multiplicity of substantially rectangular and spaced apart fins mounted upon and individual to a single course, the diagonal lines of the fins being in substantially vertical and horizontal planes, and the refrigerant conduit having a a multiplicity of substantially rectangular and spaced apart fins mounted upon and individual to a single course, the diagonal lines of the fins being in substantially vertical and horizontal planes, and end means to maintain the spaced apart relationship of theconduit courses, and the refrigerant conduit having a spirally wound member inserted therein to provide a helical path adjacent the internal wall of the refrigerant conduit.

5. In a cooling unit, the combination of parallel spaced apart refrigerant conduit courses, a multiplicity of substantially rectangular and spaced apart fins mounted upon and individual to a single course, the diagonal lines of the fins being in substantially vertical and horizontal planes, and end means to maintain the spaced apart relationship of the conduit courses, the said end means comprising a plate with slots,

- through which project the return bends joining RICHARD W. KRITZER. ANTHONY F. HOESEL. 

